Package



1961 c. H. TURPIN I 2,996,235

PACKAGE Filed Nov. 5. 1959 2 Sheets-Sheet l 1961 c. H. TURPIN 2,996,235

PACKAGE Filed Nov. 5. 1959 2 Sheets-Sheet 2 INVENTOR flew/e155 A. EG /N 2,996,235 Ice Patented Aug-4. 15, 1961 2,996,235 PACKAGE Charles H. Turpin, Minneapolis, Minn., assignor to The Pillsbury Company, Minneapolis, Minn., a corporation of Delaware Filed Nov. 5, 1959, Ser. No. 851,183 4 Claims. (Cl. 229- 37) This invention relates to packages which are made from folding cartons, and particularly those which are leakproof, siftproof and greaseproof in nature.

In the past, numerous attempts have been made to pro- 'vide containers which, besides being leakproof and siftproof, are greaseproof, particularly where the contents are in the nature of fluid or fluent material, such as cake mixes, dried milk, powdered sugar, etc., which contain fats or oil.

It has beenfound that it is difficult, if not impossible, to achieve the desired ends by utilizing cartons of conventional construction, the closures failing to remain tight and liquidproof throughout. Moreover, the cut edges of the carton flaps usually contact the contents; and the shortening or other fats or oils wick through the board of the carton from the cut edges spoiling the outward appearance of the carton and damaging the ingredient balance of the product.

Numerous changes have been proposed in the construction of the carton itself in order to overcome the foregoing difiiculties, but the cost thereof has either been prohibitive, or the construction so complicated as not to be practical for commercial operations.

It is among the objects of the present invention to provide a durable greaseproof, leakproof package which overcomes the difiiculties referred to and which is also easy and inexpensive to manufacture and utilize.

The invention, then, comprises the features hereinafter fully described and as particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative of but several of a number of ways in which the principles of the invention may be employed.

In said drawings:

FIGURE 1 is a plan of a carton blank which embodies the teachings of the present invention;

- FIGURE 2 is a perspective illustrating the upper portion of an unsealed package with the rear and front flaps and the end tabs in open relationship;

FIGURE 3 is a view similar to that of FIGURE 2, but disclosing the first step in closing the end opening 'of the package; FIGURE 4 discloses the second step in closing the end opening with the last step or phase to be completed; and FIGURE 5 is an enlarged view of a tear-corner.

Referring more particularly to the drawings, the blank for forming the carton of the present invention has formed in succession thereon a rear wall 1, end wall 2, front wall 3, end wall 4, and a glue flap 5 which may be carried by, and extend along, the outer side edge of either the rear wall 1 (as shown) or the front wall 3. It will be observed that the free edges of the glue flap are formed at right angles, and the reason therefor will appear hereinafter.

As represented in FIGURE 1, the blank is provided with conventional upper and lower score lines from which upper and lower tabs and flaps extend and which are adapted for inward folding movement to effect the closure of the ends of the carton.

More specifically, the rear wall 1 carries upper and .lower flaps '12 which are of substantially the same shape as the horizontal cross-sectional area of the carton, but

slightly smaller to permit of interfitting relationship therewith.

The end walls 2 and 4 are provided at both top and bottom with foreshortened tabs 14 which are but slightly narrower than the depth of the interior of the carton; while the front wall 3 carries upper and lower rectangular final closure flaps 16 which have substantially the same dimensions as the horizontal cross-sectional area of the completed package.

The outer side edges of the foreshortened tabs 14 may, if desired, be undercut and filleted, in the manner well known in the art.

Referring to FIGURES l and 2, a so-called tear corner is provided at each of the corners defined by the upper and lower flap 12, and the foreshortened tabs 14 and final closure flaps 16 with which they cooperate, i.e., three of such corners being both at the top and bottom of the carton. In the punching and creasing operation, the cuts defining the aforementioned elements 12, 14 and 16 are terminated at a point which is short of that which is necessary to permit their being folded inwardly along their respective crease lines, whereby some carton material is left at the inner ends of said cuts, as illustrated at 18in FIGURE 1.

Upon folding these elements 12, 14 and 16 outwardly, the carton material remaining at the inner ends 18 of the cuts which separate them is torn in such manner as to form a fiber tuft, as illustrated at 18a in FIGURE 2. These fiber tufts 18a extend substantially at right angles to the end plane of the carton formed by the overturned or inwardly folded elements 12, 14 and 16, providing bulk at these corner points and forming a greaseproof joint with the appropriate portions of a substantially rectangular sealing sheet 20.

This substantially rectangular sealing sheet 20 is of relatively thin and flexible material, and one of them is secured to the inner surface of each of the flaps 12 which, as before mentioned, are of substantially the same shape as the horizontal cross-sectional area of the carton, but slightly smaller, etc.

As will be observed, the inner edge of the rectangular sheet 20 is straight and extends in close parallelism with the inner edge of the flap 12 by which it is carried. However, the other three edges of the sheet 20 project somewhat beyond the edges of the flap, as shown at 20a, 20b and 200, the outer ends thereof being chamfered, as shown at 21.

It is essential to the present invention that the rectangular sealing sheet 20 be formed of a material which is greaseproof, such as glassine.

In the various figures of the drawings, the inner faces of the rear wall flap 16 and the adjoining end wall tabs 14 are shown as provided with a suitable adhesive, as shown at 25 and 26, respectively. The rear wall flap 16 is further provided with an intermediate adhesive strip 27.

In FIGURE 2 of the drawings, [the blank is shown as assembled into a carton with the aforementioned flaps or tabs in open relationship. In this position, the inner surface of the narrow end wall 4 of the blank is overlapped by glue flap 5. Subsequent to scaling, the longitudinal raw edge of the glue fiap 5 is coated with some suitable material, such as wax, saran or methyl cellulose, thus forming what is known as a manufacturers joint which insures against grease wickage through the porous raw edge. To insure against grease wickage at the joint formed by the two end raw edges of the glue flap 5, and closed flap 12, the end raw edges of flap 5 are out at right angles to the longitudinal raw edge thereof. Thus, when flaps 12 are in closed position, rectangular sealing sheets 20 positively engage and entirely cover the two 3 end raw edges of flap 5, thereby preventing grease wickage through those edges.

After the carton has been appropriately filled, the rear wall flap L2 is folded downwardly into position. in so doing, the projecting edge strips 20a, 20b and 200 of the rectangular sheet of thin and flexible material 26 are forced upwardly by contact with the adjacent portions of the inner surfaces of the carton and, of course, with the fiber tufts 18a which are formed at the tear corners due to the foreshortening, as at 18, of the cuts which separate the various flaps and tabs.

Next, the foreshortened tabs 14 of the end. walls 2 and 4 are folded downwardly onto the upper (and outer) surface of the. rear wall flap 12, thus forcing the projecting edge strips 20a and 200 to fold downwardly onto the latter. With the foreshortened tabs 14 in downwardly folded position, their adhesive strips 25 and 26 (now extending cross-wise of the carton) become effective to hold in position the rear wall flap 12 and the rectangular sheet of thin and flexible material which it carries.

Then, the front wall flap =16 is folded downwardly onto the previously folded elements, thus providing total edge contact with the right-angular corners of the glue flap 5 and again sealing up the raw edge of a lap joint. In such position, its inner and outer adhesive strips 25 and 26, respectively, come into coextensive contact with the immediately underlying portions of the package. It will also be observed that the undercutting or profiling of the outer side edges 14a of the foreshortened end wall tabs 14 enables the intermediate adhesive strip 27 to make direct contact throughout its length with the mid-section of the rear wall flap 12, except for the portions of the folded edge strips 20a and 2% which overlie the said flap.

It will be understood that the gluing pattern shown and described is illustrative only; and that numerous changes may be made therein.

Pressure is applied in conventional manner to complete the seal.

When the various flaps and tabs are folded in the sequence described, the overlapping edges 20a, 20b and 280 of the sheet 20 become firmly adhered to those portions of the carton with which they come in contact.

It is preferable that both ends of the package of the present invention embody the elements described herein and claimed hereinafter. However, it is contemplated that, under certain conditions, one of the ends of the package may be closed by other eifective means.

While I have shown and described certain specific embodiments of the present invention, it will be readily understood by those skilled in the art that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A leakproof, greaseproof package comprising a rectangular container body formed of a rear wall, a front wall, and two end walls, a flap hinged to each of said rear and front walls, a foreshortened tab hinged to each of said end walls, one of said flaps being of substantially the same overall dimensions as the horizontal cross-sectional area of the container, the other flap being approximately the same size and shape as, but slightly smaller than, the area of the open end of said container body, a rectangular sealing sheet of thin and flexible material secured to the inner surface of said smaller flap, one edge of said rectangular sealing sheet being disposed to extend in close proximity to the inner and hinged edge of its carrying flap, the other edges of said rectangular sealing sheet projecting beyond the corresponding edges of the carrying flap for a suflicient distance to insure that the closing of said carrying flap will result in the formation of upturned edges of said rectangular sealing sheet along the projecting areas aforesaid, said foreshortened tabs being adapted to overlie said carrying flap, the

other and larger of said two aforementioned flaps being adapted to overlie said foreshortened tabs.

2. A leakproof, greaseproof package comprising a rectangular container body formed of a rear wall, a front wall, and two end walls, a flap hinged to each of said rear and front walls, a foreshortened tab hinged to each of said end walls, one of said flaps being of substantially the same overall dimensions as the horizontal cross-sectional area of the container, the other flap being approximately the same size and shape as, but slightly smaller than, the area of the open end of said container body, a rectangular sealing sheet of thin and flexible material secured to the inner surface of said smaller flap, one edge of said rectangular sealing sheet being disposed to extend in close proximity to the inner and hinged edge of its carrying flap, the other edges of said rectangular sealing sheet projecting beyond the corresponding edges of the carrying flap for a suflicient distance to insure that the closing of said carrying flap will result in the formation of upturned edges of said rectangular sealing sheet along the projecting areas aforesaid, said foreshortened tabs being adapted to overlie said carrying flap, the other and larger of said two aforementioned flaps being adapted to overlie said foreshortened tabs, and adhesive areas on the inner surface of said larger flap and the inner surfaces of both of said foreshortened tabs.

3. A leakproof, greaseproof package comprising a rectangular container body formed of a rear wall, a front wall, and two end walls, a flap hinged to each of said rear and front walls, a foreshortened tab hinged to each of said end walls, one of said flaps being of substantially the same overall dimensions as the horizontal cross-sectional area of the container, the other flap being approxi mately the same size and shape as, but slightly smaller than, the area of the open end of said container body, and a rectangular sealing sheet of thin and flexible material secured to the inner surface of said smaller flap, the adjacent edges of adjacent flaps and tabs at each of the corner junctions being torn edges located directly adjacent such corner junction and providing a tuft of free fibrous strands directly at each of said corner junctions, one edge of said rectangular sealing sheet being disposed to extend in close proximity to the inner and hinged edge of its carrying flap, the other edges of said rectangular sealing sheet projectingbeyond the corresponding edges of the carrying flap for a sufficient distance to insure that the closing of said carrying flap will result in the formation of upturned edges of said rectangular sealing sheet along the projecting areas aforesaid, said foreshortened tabs being adapted to overlie said carrying flap, the other and larger of said two aforementioned flaps being adapted to overlie said foreshortened tabs.

4. A leakproot, greaseproof package comprising a rectangular container body formed of a rear wall, a front wall, and two end walls, a flap hinged to each of said rear and front walls, a foreshortened tab hinged to each of said end walls, one of said flaps being of substantially the same overall dimensions as the horizontal cross-sectional area of the container, the other flap being approximately the same size and shape as, butrslightly smaller than, the area of the open end of said container body, a rectangular sealing sheet of thin and flexible material secured to the inner surface of said last-mentioned flap, the adjacent edges of adjacent flaps and tabs at each of the corner junctions being torn edges located directly adjacent such corner junction and providing a tuft of free fibrous strands directly at each of said corner junctions, one edge of said rectangular sealing sheet being disposed. to extend in close proximity to the inner and hinged edge of its carrying flap, the other edges of said rectangular sealing sheet projecting beyond the corresponding edges of the carrying flap for a suflicient distance to insure that the closing of said last-named flap will result in the formation of upturned edges of said rectangular sealing sheet along the projecting areas aforesaid, said foreshortened tabs being adapted to overlie said last-mentioned flap, the other and larger of said two aforementioned flaps being adapted to overlie said foreshortened flaps, and adhesive areas (m the inner surface of said larger flap and the inner surfaces of both of said foreshortened tabs 6 References Cited in the file of this patent UNITED STATES PATENTS 

